#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e3+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
multiset<LL>s;
LL a[maxn],b[maxn];
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL n;cin>>n;
    for(LL i=1;i<=n;i++) cin>>a[i];
    for(LL i=1;i<=n;i++){
        cin>>b[i];
        s.insert(b[i]);
    }
    vector<LL>ans;
    for(LL i=1;i<=n;i++){
        LL num=a[1]^b[i];
        multiset<LL>T=s;
        T.erase(T.find(b[i]));
        bool flag=true;
        for(LL j=2;j<=n;j++){
            LL need=num^a[j];
            if(!T.count(need)){
                flag=false;
                break;
            }
            else{
                T.erase(T.find(need));
            }
        }
        if(flag){
            ans.push_back(num);
        }
    }
    set<LL>lll;
    for(auto i:ans){
        lll.insert(i);
    }
    cout<<lll.size()<<"\n";
    for(auto i:lll){
        cout<<i<<"\n";
    }
   	return 0;
}
